GM Style Brake Bleeder Kit For Combination Valves ✔️ Set of 4 blue bleed tools fits Pv2 Pv4 gm combo disc drum setups This set includes four brake bleeder valves designed specifically for GM style combination units often found on hot rods, street rods, pickup trucks, and vintage sedans. Technician install these handy bypass pieces to lock the internal low pressure exhaust function while purging air from your hard brake lines, which prevents the warning indicator from tripping during routine service on disc/disc and disc/drum configurations. ✅ Compatible with AC Delco 172-1353 172-1371 gauges plus PV2 PV4 valves ✅ Locks low pressure exhaust stem to stop the warning light from flickering ✅ Slips right onto the bleeder port without messing up the metering setup ✅ Bolt-up ready for a ton of GM platform trucks sedans and custom builds 💡 How does locking the low pressure exhaust stop a gm combo gauge from tripping during brake service? A handy bleeder solution blocks the vent so pressure stays high while you push air out. - Stops the warning indicator from flipping when you crack the caliper bolts - Pushes air through the whole circuit faster without fighting the check spring - Lets you purge both circuits without switching hoses or adding new plugs - Wipes the mess away cleanly since you control the flow direction exact ✝️